Valve gear for reciprocating engines



J. OLSSON VALVE GEAR FR REQCIPROCATING ENGINES Nov. 5, 1940.

Fueafualrch 18, 193e s sheets-sheet. 1

VALVE GEAR FOR RECIPROCATING ENGINES Filed March 1s. 195s s sheets-sheet 2 ,zr/92 4142A' 41424746 740/5 46 7.27

NOV. 5, 1940. J, OLSSON 2,220,173

VALVE GEAR FOR RECIPROCATING ENGINES Filed March 1e. 193s s sheetsfshee't s 75 75 74l 4 76 677' 8" M 7 r 4 5? 13 58 271s lq 25 6o f '12 637 I 12 62 I 65 A F 1ov 68 72 22 E? H` 5 s n 1 m rm rm mn rm= Patented Nov. 5, 1940;'

UNITED STATES z.22o,1'z3 vALvE' GEAR Foa nnclrnocarmc- ENGmEs Johannes Olsson, Goteborg, Sweden, asslgnor to Aktiebolaget Gtaverk corporation oi' Sweden Application March 1s,

en, Goteborg, Swedem'a 193s, scrisl'naisacav I In Sweden September 17, 1935 The present invention relates to the valve gear of reciprocating engines having iixed cylinders.. and rotating crank shafts, and the invention is particularly directed to 4such valve gears, in which -the movements of the respective valves are controlled by guiding means provided on the main crank shaft itself. -Howev particularly in multiple cylinder-*engines it has proved diillcult to provide a valve gear, which does not increase the dimensions of the engines, particularly with regard to their length and breadth, and which enables the pertaining mechanisms and parts to be so'disposed that the supervision of the movable parts o f the engine is not prevented and that the connection of the motor cylinders to two 1ongitudinallydispose'd manifolds serving as inlet and outlet manifolds for all the cylindersmay be easily achieved. -f

One object of the inventionis to eliminate these drawbacksof engines of the above mentioned type such as steam engines, Diesel engines, gas engines etc., and the invention is substan- ,tially characterized by the fact that the valves, which maybe spring-loaded, are'connected by means o f a beam with two rodsconnected with Vthe ends of said beam and disposed in the same way in the longitudinal direction of the respectivecy der, and that guiding means are provided on the crank arms of the main crank mechanism of the respectivefworking "cylinder or on counter weights provided or formed thereon, each one of said guiding means being adapted to directly or indirectly actuate one of said rods. According to the invention the rods may be $5 disposed within sectors with the cylinder axis as ,centre and extending over 6Q counted from the longitudinal centre plane of the engine. f

' Other.. .features of noveity'will be hereinafter disclosed in connection with the description of n two embodiments of the invention illustrated in` thepaccompanying drawings, in which: Fig. l is a vertical cross section of a Diesel engine according to the invention,

\ Fig. 2 a side elevation and Partial longitudinal i 45 section of the engine according to Fig. l.

Fig.- 3 a section larger scale.. v lFig. t a horizontal. sectionon Fig. 3, 5o., Fig. 5 apartial longitudinal sectio illustrating the connection between the beam and the tie rods f employed *inthe valve gear ofl the engine illus- .trated in Figs. 1 and 2, and

' Fig.l 6 a detail showing an abutment employed lo in\the valve gear-.illustrated in Figs. 1 and 2.

on line III- min Fig. 2 on a :v -'rv in Cl. 12S-65) Fig. 'I is a vertical cross section through the cylinder and crankcase of a Diesel engine according to a second embodiment ofthe invention, Fig. 8 a side elevation and partial longitudinal section of the engine illustrated in Fig. '1, 5 Fig. 9 `a plan View of the 'engin illustrated'in Figs. 'l and 8, and.

Fig. 10 a section on line X-X in Fig. 9 ofy the top of a combustion cylinder of the engines illustrated in Figs. 1. 2, 'l and. 8. 'I'he two cycle solid injection Diesel engine` illustrated in Figs. 1-6 comprises a crankcase I, 2 having combustion cylinders 3 bolted to its upper ,half 2. The top of each .combustion cylinder is covered by a cylinder head l in the usual manner. lo AThe crank shaft 5 is mounted in bearings 6 in the crankcase and the crank-arms 1, 8 are integral with the crank pin 9, which is. connected .with the piston I0 by. means of a connecting rod il, which is partially broken away in Fig. l. The 20 cylinder 3 and the cylinder head l are provided with cooling jackets l2 and I3, respectively. Openings Il for the introduction of. scavenging and charging air are provided in the lower portion of each cylinder 3, and an exhaust valve 25 Vl5 is disposed in the cylinder head of each combustion cylinder. scavenging air is supplied through a conduit I6 common for both cylinders, and the combustion gases are exhausted through a conduit i1. 'I'he scavenging and charging air is 30 compressed in a double acting reciprocating compressor, which is built together with the internal combustion engine. The compressor comprises acylinder I8 provided with a cylinder head i9 and accommodating a double piston 2li connected 35 through a piston rod 2| and a connecting rod 22 to the crank shaft 5. Spring-loaded inlet valves 23 and 2l are provided in the top and bottom, respectively, of the compressor cylinder. Springloaded outlet valves 25 and .26 are provided m40 valve'housings 21 and 28, respectively, secured to the top and bottom of the compressor cylinder I I and communicating through a4 manifold 2 9, Fig. 2,with the air supply conduit I6 of the inter# nal combustion engine. 5

vvAccording to the invention the valves i5 are controlled by guiding means provided on the crank arms and comprising cams 30 and 3| formed' on the counterweights 32 and 33, respectively, which are bolted to the crank arms 5o 1 andy 8. These. cams cooperate with two doubl-armed levers 34 and 35 journalled on pivots 36 secured in the vupper half 2 ofthe crankcase. The leversV 34, carry rollers 31' at onel end, which roll on the'gu'iing cams ofthe counterare pivotally connected with tie rods 38, 39 pi'votally connected at their upper ends with the Yends of a beam 40. At one end-the tie rods are preferably provided with means for adjustment of their length. Said means may. for instance, comprise two nuts 4I, 42 screwed onto the ripper' ends of the tie rods, the nut 42`r havdesign of the connection between the tie rods- 38, 39 and the beam 48 results in a certain movability and elasticity of the connection between said parts so that the valve gear does notV get completely inoperable even if one of the tie rods 38, 39 by some reason should stick or break.

then be dispens Naturally, the valve I5 may be connected with the beam 40 in any manner. Figs. 3 and 4 illustrate a valve stem connection, which comprises a balljoint providing a certai movability `between the beam 40 and the va e stem, so that the latter is not subjected toc bending stresses originating from the beam 48. For this purpose two blocks 48 are secured on the upper end of the valve stem, s aid blocks being partially provided with spherical surfaces resting in `spherical bearing cups 49, 53 fitted in a recess in the middle of the beam 40 and secured by means of screws 5I, as illustrated in Figs; 3 and 4. Apart from a certainv movability thisg'arrangement enables the cylinder head and the valve to be removed without disconnection of the beam 48 and the other parts of the valve gear. Naturally, a spring dis sed between the cylinder head and the beam oaxiallywith the valve may be provided for moving the valve towards its seat, as will be hereinafter disclosed in connection with the embodiment illustrated in Figs;

7, 8 and 9, an'd\o`bviously the springs 46 may K ed with. In order to limit the movements of the tie rods 38,39 and -to prevent the rods and the double-harmed levers 34, 35 from takingunsuitlable or dangerous positions, for instance upon valve stem breakage or other defects, resilient abutments 52 are provided onprojecti'ons 53 from the upper half 2 of the crankcase and prevent the levers 34, 35 from making too large movements. These resilient abutments may comprise a rod 52 actuated by a spring 54 interposed bel tween a washer 55 on saidA rod and the projection 53, as illustrated inA detail in Fig. 6.

During the main part of each revolution of the crank shaft the rollers 31 are -out of engagement with the counterweights 32, 33. During this period the springs 46 and the gas pressure in the cylinder keep/the valve I5 against its seat and the beam 4o with the ne rods at, ss lifted. Then the rollers 31 are situated at such a distance from the centre of the crank circle that a certain play exists between 'the rollers and the circle 56 indicated -in dotted lines on the, counterweights. travel in under \the rollers 31 the rollers move over the cams 36, 3|. The two tie rods 38, 39

are then pulled downwards by the levers 34, 35

and the beam A4I) is moved downwards and Opens When the counterweights v 2,220,173 weights. The opposite ends of the levers 34, 35j

the respective valve I5 against the action of the springsl 46. The arrangement of the beam has then, among others, the advantage that irregularities in the cams 30, 3l of the two counterweights are equalized and that the valve gear is symmetrical relatively to the cylinder centre. A

further advantage of the valve gear illustrated in Figs. 1 and 2 consists in the fact that the rods 38, 39 are only subjected to tension, and, since the valves I5 are vonly actuated yduring periods of the piston motion, when a low pressure prevails in the cylinder, the forces acting upon the rods and the entire valve geagr are relatively smallso that said parts may be given small dimensions.

The invention is of special importance for such two cycle engines, in which fuel is'supplied to the cylinder by a pump operated by the compression pressure in the cylinder, (but natux'allyl any known fuel injection system may bel employed in connection with the invention. In

Fig. 2 a fuel injection valve 51 is iridicated. The

fuel injection system just mentioned is, however, of. special advantage and will therefore be further described below in connection with Fig. 10..

A further embodiment of the invention is i1- lustrated in Figs. 7, 8, 9 and 10. In these gures the same reference numerals as in Figs. 1-6

have been used to indicate parts having their equivalence in Figs. 1-6, and consequently only the differing parts will be dealt with in the /following description of these figures. and 9 illustrate a two cyclefDiesel engine comprising two combustion cylinders 3 and a conipressor cylinder I8 adapted to produce the necessary charging and scavenging air. `The compressed air from the compressor is conducted to the cylinders. 3 through an air manifold 58 communicating at the top and bottom with the compressor .cylinder and through the conduit 59 with the air inlet openings 60 of the combustion cylinders. 'I'he air inlet is controlled lby the valve 81. The combustion gases are exhausted from the combustion cylinders through exhaust ports 62 rand the exhaust conduit 63 common for both cylinders. 'I'he crank arms 1 and 8 are integral Figs. ,"1, 8

with the counterweights 64 and 65, respectively,

which have cams 6661 provided thereon. Double-armed levers 68 and 89 are pivotally mount- 'ed on pivots 10, 1| provided on projections 6I` from the .upper -half 2 of thecrankcase. The double-armed levers 68, 69 are provided at one end with lrollers 12, which in normal position of the levers are positioned coaxially at a distance from the crank circle centre represented by the circley 56 irr Fig. 7.- In-Fig. '7 the cam 61and the lever 68, which lie above the plane of the drawing, are indicated in'dotted lines and this figure illustrates the difference in the conilguration of the cams 66 and 61 necessary to' enable the levers to move simultaneously and synchro,

nously. The outer ends of the levers 68, 69 are pivotally connected by means of tie rods 13 and 14, respectively, with' a beam 15, which is disposed above the top of the cylinder and forms an angle of 45 with the longitudinalcentre plane o the engine, as illustrated in Fig. 9. At the cen re of the beam 15 the stem of the air inlet valve 81 isA secured, and a spring 16 coaxial with the valvestem is interposed between the cylinder head4 and the beam 15 and tends to move the valve l5 against its seat and the beam 15 with the tie rods-13 and 14 upwards.

The, connection between the beam" and the valve 75 Figs. 3 and 4.

40 Consequently, the invention is not limi 55' nal centre plane as 75. movable to and from `assioma stem may be of the construction illustrated in Fig. is a section i on line-X-Xl in Fig. 9 through the top of a combustion cylinder of a Diesel engine according to the invention and illustrates a fuel supply device provided in the cylinder head 4. A differential piston 11 is mov able in a bore 18 in the cylinder head 4, which bore fcommunicates with the compression cham-s 10 ber of the cylinder through a duct 1.9'. A spring 80 tends to move the piston 11 downwards. The small end 8l of 'the differential piston is movable in a bore 82 in a block 8,3, which communicates with the fuel injection valve.51 througha pipe 84 if" and with the fuel supply pipe 85 through ducts in the block 83 controlled by a spring-loaded ball valve 88. When the valve 81 is closed and the working piston i0 moves towards the cylinder top, the compression pressure lin the cylinder 20 rises sufficiently to force the diierential piston 11 upwards and thereby to produce fuel injectionl intothe cylinder. Upon the downward stroke of the piston l0 the spring-80 or thepressure of the fuel in'the pipe 85 causes the differential' piston to move downwards and a new quantity' of f'uel to loe-introduced intotne bore a2. The fuel injection system illustrated in Fig. 10, which may 'naturally be used in all the embodiments of the' present invention illustrated inthe drawings, has the advantage that the usual cam shaft 4iiiployed for operation of the; fuel injection apparatus in solid injectionv internal combustion engines may be dispensedwith.

'Ihe embodiments of the invention `above described and illustrated on the drawings should` only be considered as examples, and the valve gear according to the invention' may naturally be modified in several different ways without departing from the principle of the invention ed to two cycle solid injection .Diesel engines of the types illustrated in the drawings but 'may also be employed with advantage in other Diesel engines as well as in other inte al combustion engines such 45 as explosion engines, gas engines, etc., and theL invention may also' be employed in -other reciprocating engines such as gas or steam engines;` The tie rods prlsed in the valve gear and .disposed substan ally parallel to the cylinderA '50 axis may be disposed in a plane, which differs from the-longtitudinal centre plane ofthe engine, and whichmay, forjnstance, fall within a sector. having its centre on the cylinder axis andextending some 60 on both sides of said longitudiillustrated in Fig. 9. The guiding means provided on the crank arms may also be formed in different ways from those illusltrated in the drawings. and the levers connected with the lower ends ofthe armed levers or may be totally dispensed with.

Y The invention' mayalso be employed in engines having inlet valvesas well as exhaust valves provided in the cylinder head and in such cases both 55 valves may be operated by means ofvalve gears according to the inven/tion.

WhatIclBim'is: 1.'In a' reciprocating-enginaa iixed working shaft, a connecting rod connecting said main working 'pistou' with said crank, a beam, an opening'in said cylinder dened by a valve seat, a

valve operatively' associated with said beam and rodsmaybe disposed 60 in different ways and may also comprisesinglesaid valve seat and adapted to control saldopening of the'working cylinder and-to open toward the interiorrof said' cylinder,

two rods connected with said beam, one on each side of said valve, two crank arms on said shaft andy 'cams provided on said crank arms adapted to simultaneously actuate said rods to operate shaft, a connecting .rod connecting Isaid main working piston with saidV crank, a .beam -substantially in the longitudinal center plane of the engine, an opening in said working-.cylinder denedby a valve seat, a valve movable to'and from said valve seat and Aconnected with said beam between the ends of the 'beamzand adapted-to control said opening -of the working cylinder and to open toward the'interior of said cylinder, two

rods extending substantiallywin the longitudinalv direction of said cylinder and at one'end connected with said beam with one rod on each side of said valve, twoV crank arms comprised in said f crank, and cams onsaid crank arms adapted to simultaneously actuate said rods at their opposite ends to operate the valve.

3. In a reciprocating4 engine, a. fixed working cylinder, a rotating crankshaft, amain working piston in said working cylinder, a crank on said crankshaft, a connecting rod connecting said mainworking piston with (saidfcrank, a beam, an

opening in said working' cylinder. defined by a valve seat, a valveoperatively associated `with saidbeam and movable to and from said 'valve seat and adapted to control said opening of the working cylinder and to open toward the interior of said cylinder, two rods connected with said beam, one on each side of said valve, and. cams provided on said crankshaft, and. adapted to simultaneously pull said rods Vto operate the valve. f Y

d 4. In a reciprocating engine, a fixed-working cylinder, a rotating ,crank shaft, amain working piston in said working cylinder, acrank on said crank shaft, a connecting rod connecting said ;on each side of said valve, two crank arms com'- prlsed in said crank shaft, 'and guiding means on said crank arms adapted toactuate said rods at their opposite ends to operate the valve.`

5. A valve gear for reciprocating engines havvmain working piston with said crank, a beam ing iixed`working cylinders and rotating crank z .shafts and-comprising a beani, a valve connected with said beam between the ends of the beam, two rods connected at one end with vsaid. beam -one on each lside of 'said valve, two crank arms comprised in the main crank mechanism of the respective cylinder andprovided on said crank shaft, anda counter weight on each one of said crank arms `iorminga 'cam adapted to actuate the opposite ends of said rods vto operate the valve.v l J 6. Aval-ve gear for reciprocating engines havingfixed working cylinders and rotating crank shafts and comprising a beam, avalve connected with saidbeam between the ends. of the-beam,

two rods connected at one end-'with said beam one on each side of said valve, each rod having A v v of said rod, resilient abutments provided on portions of the crankcase of the engine and adapted to confine the movements of said levers in one direction, two crank arms comprised in the main crank mechanism of the respective cylinder and -provided Von said crank lshaft, and counter weights on said crank armsl forming cams adapted to cooperate with said levers to operate said rods and thev valve.

"7. In a reciprocating engine, a iixedworking cylinder, a rotating crank shaft, a main working piston in said working cylinder, a crank on said crank shaft, a connecting rod connecting said main working piston with said crank, a beam, a valve connected with said beam between the ends of the beam and provided in the cylinder head of the respective cylinder, a spring at y each end of said bear'nA disposed between said beam and the top ot-the cylinder and acting to move said beam so as to close said valve, two

rodsconnected atone end with said beam one on each side of said valve, two crank arms in "said crank, and cams provided on said crank -arms adapted to actuate the `opposite ends of connected at one end with said beam by means of resilient ball Joint connections one on each side oi' said valve. two crank arms comprised in the main crank mechanism of the respective cylinder and provided on said crank sh'af and guiding means on said crank arms adaped to actuate the opposite ends of said rods to operate the valve.

9. In a` reciprocating solid,inj`ection combustion engine, a xed working cylinder, a rotating crank shaft, a main working piston in said working cylinder, a crank on said crank shaft, a conf necting ,rodconnecting said main working piston with said crank, a beam, a valve connected with said beam between the endsof the beam, two rods connected at one 4end with said beam one on each side of said'valve, two crank arms in said crank, cams provided. on said crank arms adapted to actuate the opposite ends of said rods to operate the valve, a diilerential'piston in the cylinder head of the respective combustion cylinder, a communicationv between the large end. of said differential piston and the compression chamber of the combustion cylinder, a fuel supv ply conduit communicating with the small end of the differential piston; a check valve in said communication, a fuel injection valve, and a communication between said small end of the differential piston and said fuel injection valve.

JOHANNES oLssoN. 

